The importance of photovoltaic diodes in solar power generation

In the square array of solar cell, diode is a very common device, the commonly used diode is basically silicon rectifier diode, in the selection of specifications to save parameters, to prevent breakdown damage. Generally, the reverse peak breakdown voltage and the maximum operating current should be more than 2 times of the maximum operating voltage and operating current. There are two main types of diodes in photovoltaics systems.

Diode for preventing reverse charging (preventing reverse current)

One of the functions of Diode for preventing preventing reverse charging (preventing charging reverse) is to prevent the current of the solar cell from being reversed to the solar cell or the square array when the solar cell or the square array is not generating electricity The second role is in the battery array, to prevent the current between the branches of the array reversed. This is because the output voltage of each branch in series can not be absolutely equal, there is always a difference between the high and low voltage of each branch, or the output voltage of a branch is lowered due to a fault of one branch, shading, etc. , the current of the high voltage branch will flow to the low voltage branch and even reduce the total output voltage of the square array. This phenomenon can be avoided by connecting anti-back-filling diodes in series in each branch.

Slocable’s Anti-Reverse Diode has a rated voltage of 1600V, an electrical isolation voltage of up to 3100V between the chip and the substrate, glass passivated chip soldered, excellent temperature characteristics and power cycling capability, and silicon carbide diodes, than the ordinary diode power consumption of more than 15% . Rated current up to 55 A. If your system has a current rating of more than 12A, this diode is recommended to protect your components.

Bypass diode

When more solar cell modules are connected in series to form a branch of the cell array or the cell array, one (or two or three) diodes need to be connected in reverse parallel at the positive and negative output terminals of each panel, this diode, which is connected in parallel at both ends of the Assembly, is called a bypass diode.

The role of bypass diodes is to prevent a component or part of a component in the square array from being shaded or stopped from power generation in the event of a failure, the series current of the components bypasses the faulty components and flows through the diode without affecting the power generation of other normal components, while also protecting the bypassed components from higher forward bias or damage due to “Hot spot effect”heating.

Bypass diodes are generally installed directly in the junction box, according to the size of the component power and the number of batteries, the installation of 1 ~ 3 diodes.

The by-pass diode is not required in any situation, when the components are used alone or in parallel, it is not necessary to connect the diode. For a few components in series and a good working environment, you can also consider the use of bypass diodes.